I wanted to write an interesting piece of code so I did partially. An asynchronous website crawler! It isn’t very useful though, I don’t think Google engineers will be interested even if it makes lovely fart sounds, which it doesn’t.

TLDR; I don’t find this method very useful for things like crawling websites, especially there is no single point of data exchange, however it looks very useful for not sequence-sensitive activities. The call itself is simple enough to understand and apply to your codebase though.

Here it is: the shiny HttpClient::sendAsync method! This time I am going to crawl my girlfriend’s blog about having cats at home, which I guess it’s worth to check out if you have a nasty fur ball already or going to have one. It’s polish language only, but for God sake, can’t you use Google translator? I am writing this blog with its help all the time. You’re welcome :).

There are a lot of crap flying around about the Bitcoin. Is it going to crush down? Is it worthless? Why did prices go down? Hell I know! Maybe people just found out “cryptocurrency” doesn’t mean “privacy” and all history of transactions are public and it’s matter of time to find out who did which transaction? Who knows… Don’t even ask me these questions, Bitcoin is a nice introduction to the thriving market of numbers aka fintech. But, what I care the most is the technology behind.

I am fine with BTC “distributed” database (blockchain, probably only cats haven’t heard about “blockchain”). Each node currently stores about 20G of transactions. It’s the same gigantic ledger for every one. Well it’s not the redundancy I would normally approve but whatever - it’s about money. “Storing money has to be expensive” - said banker.

Regardless to the market problems, do you know how your Bitcoin node connects to other nodes? I did not.

Meet Andrew - a software engineer. He is doing a lot of software engineering crap. Everyone likes him. He was a rockstar here and there. Recently, he took over the old project some other people abroad were working on for a few years. Everyone was saying that this project is a nightmare and people were quitting job because of it, but not Andrew. He was the right guy here.

— Shite, how shitty is this shitty code?! So much, so much, nananana - he was silently singing all the time reading that code. His behaviour wasn’t impressive, but people kept thinking he is a genius. Every weirdo has to be one. Unless not. Anyway, he hated that code, which had many nested ifs, not enough code coverage and, which was the worst thing in the Universe, integration tests that took ages every single time someone tried to run it.

Once he asked his manager to throw away the codebase. He would re-write it again. It would be better, shiny code that he and everyone else will understand. No doubts to it. His superior agreed, considering Andrew’s fame in the office, to get rid of the entire codebase and re-do the analysis phase, apparently missed or done in two minutes.

Software engineering accepts playing with other’s code. I struggled for a while before started doing it. I was doing it wrong though. It isn’t just the software your competition is writing. It is about all software products at all!

Now I am relaxing with Witcher 3 on my Xbox and that’s actually is fun. Don’t try to bother me, I am working now, fool!

Any HTTP Client library in Java is a hell to me. Comparing to other technologies like Groovy which have built-in APIs, Java sucks. Projects use Apache HttpClient API for trivial tasks like testing, which I consider as a brain rape because of the usage difficulties. When the HTTP client was introduced and incubated in Java 9 I was like:

Finally, we have our HTTP client, at least for testing!.

Now it’s officially moved to java.net.http package. I had to try it on my own in the home laboratory.

Recently, I wrote a blog post about performance of Java Data classes. Many people pointed me out I did not write a JMH test. Instead, I wrote simple microbenchmark on my own, based on the Java performance book. Because it is, apparently, unreliable I had to write JMH test as well and compare results - trying to explain why it’s different. Let’s answer outstanding questions.

Hello, fellow programmers! First of all, I wish you all Merry Christmas! Spend this time well, there is not many moments for rebuilding family bounds these days. This is the special, Christmas blog post. I named it that because it’s fun comparison with one of the most known Polish carols (listen it here, play it now) - “Bóg się rodzi”. The name is “God Is Born”. Polish word for God - “Bóg” - reads as same as “Bug”. How programming-ready this language is!

Today, we are going to discover the most common Java bugs I have seen in my Java journey. Hope you won’t find them under the Christmas Tree :D (that’s another polish tradition - we are putting presents under the tree).

BTW: Funny thing. Let’s go back to the day I started writing this blog. I thought I would never find enough topics to blog weekly. Now, the number is amazing. Optimistically, I should write about all of them in 2090. I am just saying - regardless to many people’s opinion, the blog exists.

It doesn’t look right. There are many values of the same (and similar, like bytes-doubles) type. On the other hand, what can be wrong with many parameters? I started to instantiate these cuboids. The order of parameters was obvious but I had to check it few times - it’s very painful. And, yet, I wrote it myself! What if someone else will try to use it?

But hey, I can create additional data classes, right? So, I created two POJOs (Dimension and Colour) and changed the constructor to:

Cuboid(Dimension dimension, Colour colour)

Parameters now are related to the purposes they serve: dimension and colour. During the code review I received an honest but scary feedback though:

Classic Daw. Are you mad? This is really inefficient way, you are creating new instances! R U MAD?!?!?!?!?!?!

It made me nervous. Is creating these classes a bad thing? We are not writing here some serious, highly-performing stuff, just regular code that helps other people to solve their problems. I was really confused - is the guy right? Many people would say that object instantiation takes too much time in JVM. They are correct, however, the next question is: “How long?”.

I needed to know. It is obviously an additional work to a computer but the advantage is significant for other programmers’ work. I had to test in on my own. Let’s do the microbenchmarking.

Do you like coffee? I am crazy about it: I love the roast one. I like an espresso rather than just regular, diluted cup of coffee. It has more aroma. Once I have made an exception: my coffee-maker made me “Espresso Lungo”. After that day my stomach hurts every time I am drinking it again. People can connect the taste or aroma with an event in a memory. I have to remove Espresso Lungo from “my personal drinks” menu.

That day, right after a stand-up meeting, my team leader called me. He said I should talk with some other guy. He was quite interested in our component we were delivering.

HTTP/3? Not so fast. The standard is still in progress but big player is using it already. Which one? Google of course - actually they implemented QUIC protocol in… Chrome 29. With 28th of October we are speaking about HTTP/3, not QUIC anymore.

There are few nice docs about the protocol and hints how to build a server. We are going to answer question “what does HTTP/3 means? Should I throw away my knowledge about HTTP stack away and learn something new?”

Writing this blog is time-boxed due to my actual work. It’s around 20-30 minutes a day. Yet the outcome satisfies me, at least in terms of my learn-how-to-write progress.

That’s why I hate problems with tools. Recently, this laptop didn’t leave my home through the window because one of my cats likes to sleep on it. Ubuntu 18.04 upgrade took Jekyll and other Ruby-based apps down for a long while. Googling, investigating and fixing the problem took me the whole time which I should spend on writing another blog post (about my first Kata exercise notes). Jekyll server wasn’t working so previewing the blog as well. I was getting mad and I asked myself “why I am not able to fix that problem for ever? How come I am not able to isolate the Jekyll service from my laptop’s issues?”. The answer was hidden in the question.

I got a brand new Hykker X Range keyboard as a gift. Its click and clack sounds are nice. It turns out that I love mechanical keyboards and won’t replace my Hykker X Range for any non-mechanical keyboard, especially for typing shitload of code and full of hate emails.

This two years period was really great, especially it helped me a lot with my wrist pain. My fingers weren’t swollen after 8 hours of working anymore which was a significant accomplishment.

Now, after two years of click and clacks which can rise from the dead, it’s broken. The space key is not working at all. Few others, like tilde, are hanging up sometimes and then I need to push them harder. I thought this is just a human feature, but it looks like pushing harder applies to switches as well.

Because of my laziness, I haven’t considered buying the second keyboard so far, especially this model isn’t longer available in Biedronka. Primal soldering skill woke up inside me and told me I need to fix the keyboard on my own.

Three years ago I wasn’t sure I am ready for remote work. Is it really as cool as some people describe?

It turns out it is!

I am sharing the 5 most important things every remote software engineer needs: seniority, trust, proactivity, security and writing. These are based on my personal, 3 years long experience of working from home for big companies and doing it well. This article is not meant to scare you about transitioning from office-based to remote work however it describes downsides of this form of software engineering.

So essentially I have overwritten the entire file I was working on yesterday!
That was 15 minutes of work, but recreate the same code without afterthoughts
I have done already in my would be almost impossible!

I was pissed off. My gf was like “you have to write it once again, not a
big deal”. I googled “how to undelete a file in linux”. It wasn’t a recipe that I
was looking for - it was only about files that were just removed, not
overwritten.

Spring is not the only solution for building web-based applications. There are few
alternatives to functions it’s delivering.

Spring is a heart of many web (but not only) projects. Most programmers
are like “start.spring.io is the only place where I kick off every project”.
Telling them they could work without it will end up with bruises and a loose
tooth.

But it’s not about why Spring is wrong. Is there any alternative to it? Why we
love it so much that nothing is good enough to use? Maciej Próchniak
presented yesterday at Confitura conference few alternatives to the most used
framework in the Web world. It is not a surprise since Maciej is a big fan of
OSGi and he mentioned it multiple times in previous talks. I was really looking
forward to his talk this year and I wasn’t disappointed at all.

Agencies. They are everywhere. If you have a Linkedin
account you know exactly what I am talking about. My incoming box reminds me of
Monty Python’s sketch. I get
plenty offers daily. Usually they are about working for companies that are
looking for specific client and project,
lol.

The existence of agencies is not bad at all. In fact, they might be really good
places to work, allowing specialist to do what he or she love to and securing
job position even for a years with many end-customers. In that case margin
agency earns is completely fair for both sides (worker and agency).

What is the bad agency then? How is it happening that people are unhappy
with job they have got? I can generalise few things that I have experienced
already. I hope that after reading this small blog post you would be able
to recognise patterns below and reject bad offers. Most of senior developers
are already familiar with these, although this might save years of shame for
inexperienced programmers. Wish you nice reading! :)

First of all - I am not against writing tests or doing TDD. This might
be misinterpreted and Uncle Bob and his TDD
approach will come here and smash
my face. I can’t understand effort put in writing useless tests. This post
presents only my personal opinion and if you are writing exactly that type of
tests you can rethink those or simply disagree. Having different opinion is not
a crime. In both directions.

If you run an IT project, you probably familiar with failures. This happen so
often that people are asking the same question “everything was alright all the
time, project was heading in a proper direction and suddenly everything
crashed”. Mostly because funds wore off. Usually no one is thinking about
developers that made a mistake. Nevertheless they are driving this project, in
fact, they are the muscles.

The truth is they tend to make a mistake. A nasty one - that can cause soon
and unexpected failure. Let’s find out what is it.